Electrical switch construction

ABSTRACT

An electrical switch construction having a support means carrying a first blade and a second blade, the blades respectively having projections extending toward each other with a rolling C-shaped spring having opposite ends provided with openings respectively receiving the projections of the blades therein. The blades each has a pair of tabs on opposite sides of its respective projection and being bent relative to the spring to provide knife edges bearing against the rolling spring in aligned relation with the respective slot of the rolling spring.

[ 1 May9,1972

United States Patent Good ....200/83 P UX ....200/67 DA UX ......200/67A UX Good...................................200/67 D a m ymm mcm m MMP957 5667 9999 wmmm nwmm 6886 0757 9 ,3 2333 m m a T M MN 0 S L Ln m AC MU A m S 0 E m L0 v EC m m .4 D r 1 [73] Assignee: Robertshaw ControlsCompany,

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[21] Appl. No.: 5,710

400/ 200/83 P An electrical switch construction having a support meanscarl'mlh 13/36 rying a first blade and a second blade, the bladesrespectively 200/67 67 83 83 MN; having projections extending towardeach other with a rolling C-shaped spring having opposite ends providedwith openings respectively receiving the projections of the bladestherein.

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References Cited The blades each has a pair of tabs on opposite sides ofits UNITED STATES PATENTS respective projection and being bent relativeto the spring to provide knife edges bearing against the rolling springin 2,170,767 8/1939 Riche....................... 2,458,518 1/19492,584,460 2/1952 v minnow 3.682.132

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INVENTOR. ARTHUR L. GOOD HIS ATTORNEYS PATENTEBMM 9 1912 SHEET 2 0F 3INVENTOR.

ARTHUR L. GOOD M,M77ms HIS ATTORNEYS PATENTEDMAY 9 I972 3.662.132

' sum 3 OF 3 BIA F G. 6

- 84 9 IOB 248 5 IIB 69B 0 8 27B 34B SIB HIS ATTORNEYS ELECTRICAL SWITCHCONSTRUCTION This invention is related to the electrical switchconstruction of applicants co-p'ending patent application, Ser. No.781,307, filed Dec. 5, 1968, and assigned to the same assignee to whomthis application is assigned.

This application relates to an improved electrical switch constructionas well as to improved parts for such a switch construction or the like.

It is well known from applicants aforementioned co-pending patentapplication that an electrical switch can be provided wherein a snapblade arrangement is provided by a rolling spring interconnected betweena first movable blade and a second movable blade, the second movableblade carrying the electrical contact that is moved during the switchingfunction.

However, it is a feature of this invention to improve upon the switchconstruction disclosed in applicants aforementioned co-pending patentapplication by providing improved engagement between the respectiveswitch blades and the rolling spring.

Another feature of this invention is to provide improved engagementbetween various operating parts of the switch construction and one ofthe switch blades thereof.

Another feature of this invention is to provide an improved switch bladefor such a switch construction or the like.

In particular, one embodiment of this invention provides a support meanscarrying the first and second switch blades with the blades respectivelyhaving projections extending toward each other and being respectivelyreceived in longitudinal slots provided in the opposed ends of arolling, C-shaped spring. Each blade has a pair of tabs on oppositesides of its projection with the tabs being bent relative to the bladeto provide knife edges engaging against the spring in aligned relationwith the respective longitudinal slot thereof. One of the blades hasvarious areas thereof formed into a partial cylindrical configuration tobe respectively engaged by operating members of the switch construction,such as the actuating plunger, the adjusting member, etc.

Also, such switch blade is formed with a substantially rectangularsection having an opening passing therethrough to define two pairs ofopposed sides of the section, a first tongue being integrallyinterconnected to one of the sides and extending away from the sectionand a second tongue being integrally interconnected to that one side andextending in spanning relation over the opening of the section. Thefirst tongue providing the interconnection to the rolling spring and thesecond tongue providing the engagement portion for the adjusting memberto adjust the snap condition of the electrical switch construction.

Accordingly, it is an object of this invention to provide an improvedelectrical switch construction having one or more of the novel featuresset forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIG. I is a perspective view of the improved switch construction of thisinvention.

FIG. 2 is an enlarged cross-sectional view of the switch construction ofFIG. 1 and is taken on line 2-2 thereof.

FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 2.

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 2.

FIG. 5 is an exploded perspective view of certain of the operating partsof the switch construction of FIG. 2.

F IG. 6 is a view similar to FIG. 2 illustrating another switchconstruction of this invention.

FIG. 7 is a view similar to FIG. 2 and illustrates another switchconstruction of this invention.

While the various features of this invention are hereinafter describedand illustrated as being particularly adapted to provide a snap actingswitch construction, it is to be understood that the various features ofthis invention can be utilized singly or in any combination thereof toprovide other types of electrical switch constructions as desired.

Therefore, this invention is not to be limited to only the embodimentsillustrated in the drawings, because the drawings are merely utilized toillustrate some of the wide variety of uses of this invention.

Referring now to FIGS. 1 and 2, the improved electrical switchconstruction of this invention is generally indicated by the referencenumeral 10 and comprises a housing means 11 formed from a pair ofhousing members 12 and 13 suitably secured together by fastening means14 to define a chamber 15 therein. A blade means 16 is carried by thehousing or support means 11 and comprises a first blade 17 having oneend 18 thereof fastened to a terminal 19 carried by the housing means 11and being provided with a terminal screw 20 for attaching an externallead thereto in a conventional manner, the other end 21 of the blade 17carrying contact means 22 and 23 on opposed sides thereof torespectively cooperate with an adjustable, fixed contact 24 and anopposed fixed and spaced contact 25 interconnected to another terminal26.

The blade means 16 also includes another blade 27 having a substantiallyrectangular section 28 provided with an opening means 29 passingtherethrough and defining two pairs of opposed sides 30, 31 and 32, 33with the side having integrally interconnected thereto oppositelydirected tongues 34 and 35 respectively being provided with free ends 36and 37. The medial portion 38 of the side 30 of the blade 27 is raisedout of the plane of the sides 32 and 33 whereas the medial portion 39 ofthe side 31 is lowered out of the plane of the legs 32 and 33 with thelegs 32 and 33 being downwardly bowed at points 40 and 41 so that thecomers 42 and 43 of the sides 32 and 33 of the blade 27 can rest onabutment means 44 and 45 of the housing members 12 and 13 to mount theblade 27 in the chamber 15.

The tongue 35 of the blade 27 is suitably shaped to reinforce the samewith a central ridge 46 extending longitudinally thereof whereas thefree end 37 of the tongue 35 is bent or formed to define part of acylindrical configuration which is engaged by an adjusting screw 47threadedly carried by an adjusting member 48 itself being threadedlycarried by the housing means 1 l.

Similarly, the medial part 38 of the side 30 of the blade 27 is providedwith a downwardly formed part 49 that defines part of a cylindricalconfiguration and is adapted to be engaged by an end 50 of an actuatingplunger 51 movably carried by the housing means 1 1.

Another adjusting screw 52 is threadedly carried by another adjustingmember 53 threadedly carried by the housing means 11, the adjustingscrew 52 engaging against an abutment 54 at the free end 55 of a blade56 having its other end 57 fastened to a terminal 58 carried by thehousing means 11, the fixed contact 24 being carried on the other sideof the end 55 of the blade 56 whereby the natural bias of the blade 56is upwardly and tends to hold the abutment 54 against the adjustingscrew 52. In this manner, the position of the fixed contact 24 relativeto the other fixed contact 25 can be adjusted by the parts 52, 53.

The blade 17 is provided with two parallel and substantially straightlegs 59 and 60 joined at the left hand ends in FIG. 5 to a cross section61 having a tongue portion 62 carrying the contact means 22 and 23 onthe opposed sides thereof.

, The tongues 34 and 62 of the blades 27 and 17 respectively havesubstantially rectangularly shaped projections 63 and 64 directed 17,other in the assembled relation illustrated in FIG. 2 to be respectivelyreceived in substantially rectangular slots 65 and 66 formed in theopposed ends 67 and 68 of a C- shaped rolling spring 69 as illustratedin FIGS. 2 and 5.

In order to support and stabilize the rolling spring 69 on theprojections 63 and 64 of the blades 27 and 17 the tongues 34 and 62respectively have a pair of tabs 70 disposed on opposite sides of therespective projection 63 and 64 and being bent with a substantiallyarcuate transverse cross-sectional configuration to provide a straightline knife edge 71 at the free end of the respective tab 70 which willengage against the rolling spring 69 in longitudinally aligned relationwith the longitudinal axis of the particular slot 65 or 66 receiving therespective projection 63 or 64.

In this manner, it has been found that knife edges 71 provided by thetab 70 obtain the maximum efiective force from the rolling spring 69 asa reasonably obtainable consistency is provided in the switchperformance and avoids a pivoting action of the blades 17 and 34 againstthe rolling spring 69 that would ordinarily produce a high stress on therolling spring 69.

Also, the switch construction 10, through the configuration of the blade27, provides a desired operating or actuating pin return force to insurea biasing force to move the rolling spring 69 through the requiredactuation thereof. In particular, this feature is provided by thecontaining means 44 and 45 holding the end portion 31 of the blade 27 sothat the sides 32 and 33 provide two cantilevered springs which arerelatively independent of the position of the operating pin or actuator51 and the calibrating means 47. Accordingly, by providing the adjustingscrew 47 and the temperature selector screw 48, the final calibration ofthe electrical switch 10 can be made without a force applied to thetemperature sensing mechanism, thus making it a one shot adjustment ifthe main arm calibration is within tolerable limits.

Normally, the switch blades 17 and 27 are held in the positionillustrated in FIG. 2 when no force is being applied to the operatingpin 51 in moving the same upwardly in FIG. 2 whereby the contact 22 isin electrical contact with the contact 24 so the current flow can beprovided between the terminals 19 and 58.

However, when the actuating pin 51 is moved upwardly in FIG. 2 eithermanually or by a condition responsive means sensing a certain condition,the same moves the blade 27 upwardly in opposition to the force of thespring leg or tongue 35 until the end 36 of the tongue 34 has rolled thespring 69 in such a manner that the same snaps the blade 17 downwardlyin FIG. 2 to move the contact 22 out of electrical contact with thecontact 24 and into electrical contact with the contact 25 to now placethe terminals 19 and 26 together, the blades 17 and 27 now remaining inthis new position by the rolling spring 69 even though the plunger oractuating pin 51 is permitted to move back downwardly to the positionillustrated in FIG. 2.

Therefore, in order to reset the switch blades 17 and 27 back to theposition illustrated in FIG. 2 after the actuation of the switch 10 inthe manner previously described, a rotatable reset member 72 is carriedby the housing means 11 and has a pair of tongues 73 for straddling thetongue 34 of the blade 27 and being engageable with the sides 59 and 60of the blade 17 when the reset member 72 is rotated in acounterclockwise direction in FIGS. 2 and by a lever member 74operatively interconnected to the reset member 72 by a rectangular slot75 thereof receiving a rectangular similarly shaped projection 76 of thereset member 72. Thus, movement of the legs 59 and 60 of the blade 17upwardly will cause the tongue 62 of the blade 17 to roll the spring 69in such a manner that the same will snap the contact 23 away from thecontact 25 and place the contact 22 against the contact 24 asillustrated in FIG. 2.

Therefore, it can be seen that by changing the configuration of theblades 17 and 27 over the configuration provided in the aforementionedco-pending patent application, not only is knife edge contact providedbetween the blades 17 and 27 with the rolling spring 69, but alsocylindrical surfaces 49 and 37 are being engaged by the operators 51 and47 to increase the bearing contact areas therebetween so as to reducewear and reduce shift in the actuating pin 51 actuating position.

Such switch construction of this invention can be modified to providefor changing the actuating pin position by means other than the manualadjusting means 48.

For example, reference is now made to FIG. 6 wherein another switchconstruction of this invention is generally indicated by the referencenumeral 10A and parts thereof similar to the switch construction 10previously described are indicated by like reference numerals followedby the reference letter A."

As illustrated in FIG. 6, the adjusting member 48 has been removed fromthe housing means 11A and a retainer 77 has been threadedly disposed inthe cooperating opening with such retainer 77 carrying an expansible andcontractible element 78 having its interior interconnected to atemperature sensing bulb 79 by a capillary tube 80. A movable wall 81 ofthe power element 78 carries an operating pin 82 that projects throughthe retainer 77 and bears against the contoured free end 37A of theblade 27A to produce new actuating pin positions of the actuating pin51A for snapping over the rolling spring 69A in the manner previouslydescribed for the condition sensed by the bulb 79. For example, thearrangement 10A of FIG. 6 could be a temperature set point change for alimit control to compensate for outdoor temperature as sensed by thebulb 79. I

As illustrated in FIG. 7, another electrical switch construction of thisinvention is generally indicated by the reference numeral 103 and partsthereof similar to the switch construction 10 previously described areindicated by like reference numerals followed by the reference letter B.

As illustrated in FIG. 7, the terminal 58 and its associated blade 56 ofthe switch construction 10 has been removed and the contact 24B is nowcarried on a terminal 83 fixed to the housing means 11A.

The reset means 72 of the switch construction 10 has been eliminated andanother reset means 84 has been added to the housing means 118 andcomprises a retainer 85 carried by the housing means 118 and having aplunger 86 passing therethrough with an enlarged end 87 thereof adaptedto bottom out against the end 88 of the retainer 85 by the force of acompression spring 89 disposed within the retainer 85 and bearingagainst an opposed large end 90 of the plunger 86.

The end 87 of the plunger 86 carries a compression spring 91 having oneend 92 fixed to the end 87 of the plunger 86 while the other end 93thereof is disposed remote therefrom and is adapted to project throughthe opening of the blade 17B and engage against the tongue 34B of theblade 27B so as to move the blade 27B downwardly relative to the blade178 when the operating pin 51B has previously caused the rolling spring69B to move the blade 17B downwardly in the manner previously described.

Thus, the operator can push downwardly on the upper end 94 of theplunger 86 in opposition to the force of the compression spring 89 tomove the spring 91 downwardly against the blade 27B to snap the blades27B and 17B back to the position illustrated in FIG. 7. When theoperator releases the end 94 of the plunger 86, the compression spring89 returns the same to the position illustrated in FIG. 7.

Therefore, it can be seen that this invention not only provides animproved electrical switch construction, but also this inventionprovides improved parts for such a switch construction or the like.

While the form of the invention now preferred has been disclosed asrequired by the statute, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. In an electrical switch construction having support means and switchblade means carried by said support means for providing a switchingfunction upon movement of said blade means relative to said supportmeans a certain amount, the improvement wherein said blade meanscomprises a single blade having a generally rectangular section providedwith an opening therethrough whereby two pairs of opposed sides of saidsection border said opening, said blade having a first integral tongueextending from one side of said section in cantilevered fashion awayfrom said section, said blade having a second integral tongue extendingfrom said one side of said section in cantilevered fashion to partiallyspan said opening, adjusting means carried by said support meansengaging said second tongue for adjusting said blade means, the sideopposite to said one side being the only part of said blade engagingagainst said support means to position said blade relative to saidsupport means, said blade means including another blade that carries amovable contact of said electrical switch construction, and meansinterconnected to said other blade and to the first-named blade toprovide for movement of said other blade upon a certain movement of saidfirst-named blade.

2. In an electrical switch as set forth in claim 1, the furtherimprovement wherein said second tongue has a free end, said free endbeing formed to define part of a cylindrical configuration, saidadjusting means engaging said formed free end of said second tongue.

3. In an electrical switch as set forth in claim 1, the further Iimprovement wherein an actuator is carried by said support means and isengageable with said one side of said section of said first-named blade.

4. In an electrical switch as set forth in claim 3, the furtherimprovement wherein said one side of said section of said firstnamedblade is formed to define part of a cylindrical configuration, saidactuator being engageable with said cylindrical configuration part ofsaid one side of said section.

5. In an electrical switch construction having support means and switchblade means carried by said support means for providing a switchingfunction upon movement of said blade means relative to said supportmeans a certain amount, the improvement wherein said blade meanscomprises a single blade having a generally rectangular section providedwith an opening therethrough whereby two pairs of opposed sides of saidsection border said opening, said blade having a first integral tongueextending from one side of said section in cantilevered fashion awayfrom said section, said blade having a second integral tongue extendingfrom said one side of said section in cantilevered fashion to partiallyspan said opening, and adjusting means carried by said support meansengaging said second tongue for adjusting said blade means, the sideopposite to said one side engaging against said support means toposition said blade relative to said support means, said blade meansincluding another blade, a rolling spring interconnected to said otherblade and the first-named blade to provide a snap acting arrangement.

6. In an electrical switch as set forth in claim 5, the furtherimprovement wherein said first tongue of the first-named blade has afree end interconnected to said rolling spring.

1. In an electrical switch construction having support means and switchblade means carried by said support means for providing a switchingfunction upon movement of said blade means relative to said supportmeans a certain amount, the improvement wherein said blade meanscomprises a single blade having a generally rectangular section providedwith an opening therethrough whereby two pairs of opposed sides of saidsection border said opening, said blade having a first integral tongueextending from one side of said section in cantilevered fashion awayfrom said section, said blade having a second integral tongue extendingfrom said one side of said section in cantilevered fashion to partiallyspan said opening, adjusting means carried by said support meansengaging said second tongue for adjusting said blade means, the sideopposite to said one side being the only part of said blade engagingagainst said support means to position said blade relative to saidsupport means, said blade means including another blade that carries amovable contact of said electrical switch construction, and meansinterconnected to said other blade and to the first-named blade toprovide for movement of said other blade upon a certain movement of saidfirst-named blade.
 2. In an electrical switch as set forth in claim 1,the further improvement wherein said second tongue has a free end, saidfree end being formed to define part of a cylindrical configuration,said adjusting means engaging said formed free end of said secondtongue.
 3. In an electrical switch as set forth in claim 1, the furtherimprovement wherein an actuator is carried by said support means and isengageable with said one side of said section of said first-named blade.4. In an electrical switch as set forth in claim 3, the furtherimprovement wherein said one side of said section of said first-namedblade is formed to define part of a cylindrical configuration, saidactuator being engageable with said cylindrical configuration part ofsaid one side of said section.
 5. In an electrical switch constructionhaving support means and switch blade means carried by said supportmeans for providing a switching function upon movement of said blademeans relative to said support means a certain amount, the improvementwherein said blade means comprises a single blade having a generallyrectangular section provided with an opening therethrough whereby twopairs of opposed sides of said section border said opening, said bladehaving a first integral tongue extending from one side of said sectionin cantilevered fashion away from said section, said blade having asecond integral tongue extending from said one side of said section incantilevered fashion to partially span said opening, and adjusting meanscarried by said support means engaging said second tongue for adjustingsaid blade means, the side opposite to said one side engaging againstsaid support means to position said blade relative to said supportmeans, said blade means including another blade, a rolling springinterconnected to said other blade and the first-named blade to providea snap acting arrangement.
 6. In an electrical switch as set forth inclaim 5, the further improvement wherein said first tongue of thefirst-named blade has a free end interconnected to said rolling spring.